Seahorse, belonging to pisces, syngnathidae, hippocampus, as a precious marine traditional Chinese medical material, known as “southern ginseng” in China, is provided with effects such as invigorating kidney, strengthening Yang, strengthening heart, hastening parturition, hemostasis, analgesic, tranquilizing and allaying excitement. Lined seahorse (Hippocampus Erectus), mainly located at the west coast of the Atlantic, is a typical tropic and subtropic type of seahorse population with strong fertility, large size and fast growth rate. In recent years, lined seahorse has been introduced from United States to China by multiple Chinese companies, and it has been bred in coastal areas such as Hainan, Guangdong, Fujian and Shandong. So far, lined seahorse has become one of the main aquaculture species in China. However, after several generations of propagation, degeneration of germplasm in lined seahorse is very severe. The inventor team of the present invention had done researches on the current situation of aquaculture in partial coastal areas of China during 2010˜2014 continuously. They found that the propagation and aquaculture pattern of seahorses in China extremely lagged behind. Inbreeding depression was so severe that the quantity of spawning from parental generation decreased by 30˜60% compared to that from primary generation, while survival rate of larva was only 15˜25% and growth rate of young seahorse decreased by approximately 30% compared to that of primary generation. Thus, at the present stage, germplasm of lined seahorse has depressed obviously and quality of larva has become one of the “bottlenecks” restricting the development of seahorse aquaculture in China.
Heterosis is a common biological phenomenon, which means a phenomenon that two parents with different genetic backgrounds hybridize with each other to generate a hybrid F1 generation with improvements in aspects such as vitality, adaptability, stress resistance and productivity as compared to the purebred. Crossbreeding is currently one of the most widely used and most successful methods for genetic improvement of animals and plants at home and abroad. In the field of aquaculture, crossbreeding is also one of the main routes for improving the present situation of aquaculture. Nowadays, crossbreeding of several aquatic animals such as Chlamys Farreri (Chang et al. 2006), Penaeus Stylirostris (Bierne et al. 2000), Oncorhynchus Tshawytscha (Bryden et al. 2004), O. Mykiss (Wang et al. 2009) and so forth has tremendously progressed. However, by far, there still hasn't been any international research or report about crossbreeding of lined seahorse.